DR. JOHAN RUDOLF KATZ ( 1880-1938)
Dr. JOHAN RUDOLF KATZ* E. HEUSER AND B. W. ROWLAND The Institute of Paper Chemistry, Appleton, Wisconsin
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H E passing of Dr. Katz removed from the field of colloid chemistry a pioneer in the investigation of the structure of complex colloidal materials, and the mechanism of their behavior, particularly with reference to the phenomena of swelling. Not only did his numerous publications present matter of fundamental importance on these subjects, but they likewise enriched the technology of industries relating to starch, rubber, and cellulose. One hundred thirty-six publications in various journals, as well as three books1 haye been left us by Dr. Katz. Among these are to be found his splendid contributions dealing with the X-ray structure of alkali cellulose, stretched rubber, starch, thin liquid films, and the X-ray evidence of the swelling mechanism. In his early years Dr. Katz was engaged in the study of bread and bread-baking, an interest which did not leave him and to which he returned from time to time throughout his active life. His interest in such a problem typified his wide range of interest, including the technical as well as the fundamental. Dr. Katz's experimental technics were not confined to those of the X-ray, and evidence of his resourcefulness may be found in the fact that he turned freely to other methods of investigation in bringing the full possibilities of modem research technics to bear on his problems. Perhaps his most valuable contribution was in the field of the swelling of complex colloids, and the forces and structural changes involved in this phenomenon. Dr. Katz began his experimental studies on swelling in the year 1910, using starch and other substances; later on he chose chiefly cellulose as the most suitable subject for his investigation, and during certain phases of his work, enjoyed the cooperation of such well-known scientists in the cellulose field as Hermann Mark, Kurt Hess, R. 0. Herzog, and others. When in 1917 X-ray analysis produced its first essential results on the cellulose fiber, Dr. Katz soon recognized its great usefulness as a tool for aiding in the elucidation of the problems with which he was occupied. In fact, he regarded X-ray analysis as one of the few experimental methods which allows us "to penetrate into the intimate mechanism of swelling." * See Frontispiece. "The Laws of Swelling," "The Staling of Bread," and "The X-ray Spectrography as an Investigation Method"; also two contributions, namely, to K . Hess's book on cellulose, entitled "Micellartheorie und Quellung der Cellulose" and to Abderhalden's Handbuch der hiologischen Arbeitsmethoden, under the title "Roentgenspektrographische Untersurhungsmethoden."
The evaluation of the results of his numerous studies on the swelling of cellulose in water appeared very satisfactorily to confirm von Naegeli's early conception of the phenomenon. Further studies were devoted to the action of electrolytes, such as aqueous solutions of metal hydroxides and concentrated salt solutions upon cellulose. Again, with an intensive use of X-ray analysis, Dr. Katz developed the conceptions of inter- and intramicellar swelling, and defined the border range below and above which swelling proceeds in different ways. I t was about this time when one of the writers (E. Heuser) met Dr. Katz for the first time. After the meeting of the Naturforscher-Versammlung in Innsbruck, September, 1924, where the then much contrasting views on the molecular weight and the structure of cellulose had been aired, the discussion was continued in a small circle afterward and it developed through Dr. Katz's appropriate and brilliant remarks into some very enjoyable and fruitful hours. With one of these remarks, a modification of which he later used in his contribution to Abderhalden's work, he referred to the difficulties involved in structural problems, and said, "Structure analysis is essentially a habit of thought, the habit of thinking three-dimensionally."t Extended studies on the thermodynamics of swelling, also including a variety of substances other than cellulose, served to complete the broad investigation. In 1932 Dr. Katz presented his theory under the title "The Laws of Swelling" to the Faraday Society in London. Dr. Katz was born in Amsterdam on April 30, 1880, the oldest son of Dr. Samuel Katz, a well-known lawyer, and Marie Katz. He was educated in the public and high schools of Amsterdam and in the University of Amsterdam. During his early educational period he prepared himself for a career in medicine, and his later interest in colloid chemistry as it relates to the fuudamentals of physiology is evidence of his capacity to perceive the fundamentals, as did the late Sir William Hardy in his fruitful decision to study colloid chemistry as the key to problems in physiology. It is recorded that Dr. Katz was a brilliant student, and under the inspiration of his eminent teacher, B. Rooseboom, he received in 1917 his Doctor's degree in chemistry on a thesis devoted to a study of the laws of swelling, and in the same year the medical degree was conferred upon him for his studies on the staling of bread. In 1920, Dr. Katz made his first trip to the United
t See also Asrsrmu. Nalurc, 136, 1007 (1935).
States, and a t that time he had more than a passing interest in the subject of neurology, an interest which had developed during his sojourn in Paris in the association with Professor Dkjerine, in Bern with Professor Dubois, and in Zurich with Dr. Jung. For a time his studies in medicine led him to undertake his own practice in Amsterdam, specializing in psychoanalysis. It was partly this interest in neurology that led him to come to the United States to deliver some lectures on the subject, and partly his family ties associated with his marriage to Fanny Bowditch of Boston, in 1917. Miss Bowditch was the daughter of the late Henry Pickering Bowditch, Professor of Physiology a t Harvard University, and for some years Dean of the Medical Faculty. Dr. Katz was active during his American visit in lecturing and publishing, in an effort to unite the three existing theories of Freud, Jung, and Adler. Upon returning to Europe from the United States, Dr. Katz found that the scientific interests, which had been his first and deepest, led him back into the field of research, and in 1923 he entered the Kaiser Wilhelm Institut fiir Faser-Chemie in Berlin, and became associated with the late Professor R. 0. Herzog and Professor Otto Gemgross. It was during this period that Dr. Katz made his discovery of the crystalline structure of alkali cellulose by the then new X-ray method. Following these discoveries, he spent two years in Upsala and Copenhagen in the laboratories of Professor Siegbahn and Professor Niels Bohr, and while in Copenhagen he made a second important discovery in observing the crystalline structure of stretched rubber. After 1926, Dr. Katz continued his own research work
in the University of Amsterdam, and a t the same time gave a course of lectures during the winter terms. This period, from 1926 to 1933, was perhaps the most enjoyable and productive of his life. At this time he was much in demand among the leading chemical concerns of Europe, being eagerly sought out for advice and special lectures for numerous research staffs. This period in Amsterdam was terminated by his acceptance of an invitation by the Soviet Government to give special lectures in Moscow and Leningrad. At the conclusion of his experience in Russia, he came to the United States again, to accept a lecturing appointment a t Cornell University, and a t the same time to make a lecture tour through the Middle West as a guest speaker of the American Chemical Society. In 1935 Dr. Katz continued his lecturing and research work a t the Massachusetts Institute of Technology a t whichtime it became apparent that his health was beginning to fail. He sought to recover his strength through a quiet summer of 1936 a t the Biological Laboratory of the Camegie Institute a t Cold Spring Hiubor, but in the fall of the year he became seriously ill with a heart disease. The recovery required almost a year, but seemed sufficiently complete to warrant the resumption of his active life and permitted him to give a paper a t the Rochester meeting of the American Chemical Society, which, however, was his last. Shortly afterward, the illness retunied with greater intensity, and he failed rapidly, until his death in Boston on the nineteenth of April, 1938. The death of Dr. Katz is deeply felt not only as the loss of a friendly colleague, but also as the passing of a brilliant and successful adventurer a t the frontier of colloid science.
